Chuck



W. N. STEVENS CHUCK Filed Jan. 4. 1927 Dec. 29, 1931.

2 Sheets-Sheet 1 Inventor Vv'iili am N. Stevens Attomogs Dec. 29, 1931.

W. N. STEVENS CHUCK Filed Jan. 4. 1927 2 Sheets-Sheet 2 Wliand- N. Stevens Attornexis Patented Dec. 29, 1931 witLLIAM Nxscmvmvs, onmaxnwoongfonrot Y y CHUCK Application :mea January f4, .19a-*1Ql sama Naomsesaf This invention: relates :to .cheeks land .has espeeial reference tofeh-ueksothe rotary type ueedwon .f-maehineA tools andlfad-apted' towbe opened andfclosed without arresting :their .ro-

i tat-'ron Thefobjeets of the-.inventionfare the provision lof simpleand'eonvenient expediente wherebythe'ehnok is :rendered self-Closing;A the `provision of' simply :constructed and easily regulated means whereby the foiree .of Vits 2O Closingfmovementfean be predetermined .and

modified "by 4the foperator; while -turtlaer .ob j eets and'advantages will become apparent as tlie l:description proeeeds.

In the 4 aecomp anying` .drawings I 'have -illustrated'ra :preferredphysicalfembodiment of my inventive idea. F ig. 1 is an axial Yseo-L tional View' of "chuek containing my 1mproeements; Figui?, isa .ffrontelevationot saoh chuck' with :parte broken away; Y.Figa .3 is .a

2@ front elevation'ofsuohfehuek with'other .parte brokenaway; 'Figi .4e-is 'al detail -.v.i,ewv of pant of the manual releasing mechanism showi-ng'a mediiied form otautomatieelosing mechanism.; Figa-is anfendelevatontof the .partssshownin Fig.--,4;-.Fig,-,6 illustrates a modified construction of the partsshowain Fig. Elli; Fig: -7 Visan end-'elevation-of `the .parts shown ill-Fig. ,6; `and Figs-8andy 9..'are respectively arl-edge view .anda `face viewofthe floating cage vand the @planetary v`pinions. ear riedthereby.l

Myimproved chuck comprises thensual centnalA cylindricaltube-.1Qhaving zat. .its vforwardfend a {iat-circular plate V2 formed with radial. slideways 3 'in which ,are mounted. the jaws 4. Rotatably eur-roumdingfthetubeal is a sleeve 5 formed with gear teeth 6 and having atV its Vforward.endan integrallange .7 .formed with :spiral grooves 8 equal ,number .to the jawsfand 'reeeiving the rrollers .9..mounted on studs 10 eanriedbythe. respective jaws whereby the flatterA are `movedradially alongtheir slideways. .jlightly Lseeured tothe tube 1 at the-opposite end of the sleeve .5 lis. a sleeve k12 havingexternalrgeanteeth.13.. Retatably surrounding the. gear .6 .is a ringy 1:5 havingin- .ternal teeth 1.6 :spaeed from .thefteeth 6 `but in the saine plane.; and nonfrotatably sur- M .roundingfthe gear. 13 isa second internal gear J supported-by -and keyed to, a fixed cylindrieal shell. 18 wv-hiehgforms .the body l.odutlie chuck and is prevented from rotating ,by bejing fastened in some way to the frame (not shown) .ofthe machine with wh-iehat is msed.

An armvtorabraeket.19'.,ishere illilstrated for this .pur-pose. Y

lnterposed.betweenthe-extennal gear. .Gand internal gea-r 16 .are v. one :or .more planetary gears y 20 meshing with ":beth .of .the sameiand interposed Vbetweei.landmeshingwith vthe .exi ter-nal gear .13 Yandinternal gear 17 are .other .planetary .gears 21.: Thegears ,2O'1and21 arie coaxial. and. are married by VV.the short Sliadts QQjournaled intheeage 23 whichdloats =in the space' between 2 thegears,y as to move .together around the .axis -oi'' the ehuek5 sassaideage .res volves, The geams 2).and21c. have two sorte of movement;A namely; an orbital.. movement around .theaX-isof the sleeve 1, andafmovw ment-of rot.ation,-eaeh.about its-ovm axis. .It

is. further fobvious that when :the-gears Maand lZ .are rig-idlyfeonneeted tey theinassoeiated members there -`.mfustabe .a-.small relative .di.-f.- ference` in the speed :of yrotation rofgangy .gear 2.1as eomparedfwith its eompwnionfgear, althoughA their .orbital speed f .is the same Thegears 5 and .12 `are sometimes .known .as sun gears to .distinguish ,them from the planet gears 2Q-.211161.21 whichrotate about-thesama 'Aeeordingmo my nventionffthe'geaes i2@ and 21 are made .of unequal sizeg-vthefdame'- tersof .6.; 16,- `13, ,and-,11 being suitably adjusted to keep the -gears QO-and 21.Coaxffal. As a resultthe rotationof Atl1e..ft11b 2-,- 1 causes the gears 21'. and Acage 23. :to` progress iaround the gear 17 which movement'v alsoY eau-ses a a relative movement betweenashegears 6 ando-16; but .owingto the. 4inequalityfof- .sizeA between 2O and 2l, the sleeve Y5 does notsrotatefatthe lead. as .the dease-.may lbe) tends to produce -fa radial .cammingfoftthe .rollers 9.'. The direeltio'n of slope-ofthe reeesses is 4solehosen las, combined with the ratio Sbetween fthe .pinions 20. and 21, will` :t'oree'the .chuok-j aws inward .m9

another. setof .teeth 24 meshingfwitha pinion .l

CTI

having a prismatic shank 26 adapted to receive a suitable key (not shown). The rotation of the ring 15 is impeded by a suitable friction device, and the force exerted on the chuck-jaws varies directly with this friction as will be obvious. This friction may be provided in numerous ways. According to one arrangement, the shell 18 is formed with a recess receiving a brake shoe 31 suitably controlled as by a radial screw 32. According to another arrangement the shank of the Vpinion 25 (which is generally made a bevel pinion so that this shank is radial although this is not essential to the invention) is provided with a braking device such as the split collar 33 shown in Figs. 4 and 5 and constricted by the tangent screw 34.

in order to gauge the degree of braking and hence the pressure on the chuck-jaws the operator naturally takes account of the angular motion of the screw 3Q or 3ft crlthe amount of resistance to the rotation thereof. This can also be made visible if desired, as for example, by the modification shown in Figs. G and .7 wherein the clamp 33L is closed by a tangent screw 34a acting through a spring 35, the head of the screw having a pointer 36 cooperating with suitable graduations on a dial 3T, the graduations here consisting of movable clips 38 having the letters R for roughing and F for finishing thereon.

In order to cut entirely through the scale which a casting or forging usually exhibits, as well as to expedite the work, it is customary to make the first cuts very deep, and this requires a correspondingly powerful setting of the chuck jaws; also the continuous pressure exerted on the chuck jaws by reason of the continuous drag on the ring 15 keeps said jaws constantly bearing against thevwork at the predetermined pressure and overcomes any tendency of the same to wort loose. This tight setting, however, frequently if not invariably deforms the work, so that before taking the nishing cut the pressure of the jaws should be relieved to some extent, although not sufficiently to release the work. The work is introduced into the chuck and the braking action applied which causes the chuck jaws to move inwardly until the reaction causes the brake to slip which then continues so long as the chuck revolves. For the first or roughing cut the brake is applied strongly after which the brake is partly released whereupon the vibration coupled with the slant of the recesses 8 and the reaction of the aws usually causes the ring 15 to advance until the reaction corresponds to this new degree of friction. In some kinds of. work this releasing` action should be assisted by the operator. Turning the ring 15 by the shank Q6 causes the release of the jaws, and all these actions occur without interference from the rotation of the chuck.

The rear of the device is closed by'an end plate 40 which Ina-y either stand still with the shell 18 or rotate with the tube 1, although 1 have here shown it as bolted to the shell. 1t will be understoood that many changes in details can be made.

Having thus described my invention what I claim is:

1; In a chuck a rotatable part having awguides, aws radially movable in said guides, an annular member rotatable relative to said first member and having spiral cam portions intel-fitting with said jaws, said annular member also having gear teeth, a second annular member rotatable relative to said first member and also having gear teeth concentric to the same axis as said first gear teeth but unequal in pitch-diameter, a non-rotatable member surrounding both said annular members, two internal gears, one surrounding each set of gear teeth hereinbefore identified, one of said internal gears being fixedly mounted relatively to said non-rotatable member, means carried by said non-rotatable member for frictionally retarding the rotation of said second internal gear, and planetary pinions connecting each of said internal gears to the corresponding toothed members, the pinions of said respective planetary systems being connected together in pairs so as to move with equal speed around the chuck axis.

2. In a differential chuck, a rotatable part, clamping jaws carried thereby, a fixed part, two planetary gear systems coaxial with each other and with said rotatable part, each of said systems comprising a sun gear, a series of planet gears rotatable therearound, and an internal gear surrounding each set of planet gears, said systems having a ratio other than one to one, means compelling planet gears of the two systems torotate together about the chuck axis, means positively securing the sun gear of one system and the internal gear of the other system, one to the said rotatable part and the other to the said fixed part, means frictionally retarding the progressive tendency of one of said plauetary systems created by the difference in ratio between it and the other system, and means for transforming said progressirfc tendency into clamping pressure upon said jaws.

3. Tn a chuck a rotatable part having jawguides, jaws radially movable in said guides. an annular member rotatable relative to said first member and having spiral cam portions interitting with said jaws, said annular member also having gear teeth, a second annular member rotatable relative to said first member and also having gear teeth concentric to the same axis as said first gear teeth but unequal in pitch-diameter, a nonrotatable member surrounding both said annular members, two internal gears, one

surrounding each set of gear teeth hereini ai.

beata.

4. In a differential chuck, in combination, a rotatable part having jawguides, jaws radially movable in said guides, two planetary gear systems carried by said chuck, each system comprising a sun gear, planet gears, and an internal gear the planet-gears of said two systems being of unequal size and connected together in pairs, one of the sun gears being rotatable with the chuck, the other ofv said sun gears having camming portions cooperating with said jaws, one of the internal gears being liXed, and means for applying a regulable braking action to the other internal gear.

5. In a differential chuck, in combination, a rotatable part havingv jaw-guides, jaws radially movable in said guides, two planetary gear systems carri-ed by said chuck, each of said systems comprising a sun gear, planet gears, and an internal gear, the planet-gears of said two systems being'of unequal size and connected together in pairs, one of the sun gears being rotatable with the chuck, the other of said sun gears having camming portions cooperating with said jaws, one of the internal gears being fixed, and means for applying both an limpositive braking Aaction and a positive anticipating movement tothe other of said internal gears.

G.A In a differential chuck of the type comprising two coaxial planetary'gear systems, each system comprising aA sun gear, ,planet gears, and an internal gear which surrounds and meshes with said planet gears th-e planet gears of the two systems being secured together in pairs so as to revolve together abouty the chuck axis, the improvement which consists in making the planet gears of the two systems of unequal size and providing a brake to oppose the drifting action thereby produced on one of said systems'.

7. In a chuck, a. rotatable part having jawguides, jaws radially movable in said guides, an annular member rotatable relative to said rotatable member surrounding both said annular members, two internal gears, one surrounding each set of gear-teeth hereinbefore identified, planetary pinions connecting each of saidV internal gears to the teeth of the corresponding annular member, the pinions of said respective planetary systems being connected together so as to revolve at equal speeds about the chuck axis, means for retarding the rotation of at least one of said internal gears, while also enabling the rotation of at least one of said internal gears against friction; additional gearteeth carried by one of said internal gears, and a manually operable pinion carried by said non-rotatable member and meshing with said last named gear-teeth whereby independent movement can be imparted to said internal gear.

8. In a chuck, a rotatable part having aw guides, jaws radially movable in said guides, an annular member rotatable relative to said first member and having spiral cam-portions interfitting with said aws, said annular member also having gear-teeth, three additional annular members coaxial with said iirst annular member and also having gearnteeth concentric to the same aXis as said first gear-teeth, two of said three last named annular members constituting respectively the internal'and external gears of a'planetary system, and the third of said annular members cooperating with said first annular member to form the internal and external gears of a second planetary system, the internal gears of said two planetary systems being unequal in pitched diameter, sun-'gears located between and meshing with the internal and external gears, a fourth annular member located between said respective sun and planet systems, and having said sun-gears rotatably mounted at opposite sides thereof; in combination with means for applying frictional retarding force to at least one of said four last named rotatable members, and means including an operable pinion and auxiliary geary teeth meshing therewith'for imparting an additional rotational movement to one of said :rfmular members other than the first and In testimony whereof I hereunto aix my first member and having spiral cam portions y equal in number to said first gear-teeth, a non-- 

